To use Lily on your local machine, you'll first need to build it. Building the interpreter can be done in a few commands. You'll need two tools first:
Grab the Lily source code through whatever means you'd like. Open up a command-line prompt in the Lily directory and issue the following:
cmake . make make install
The result of the above is an executable named
lily and a library that your
programs can link to named
The following configuration options can be passed to
cmake to alter the build:
-DWITH_SANDBOX=(on|off): Defaults to
off. If this is set to
on, then the
website sandbox will be built. This option requires
emscripten to exist and be
loaded in the current environment. An error is printed if either is lacking.
Create a file called
hello.lily and save the following to it:
print("Hello, world!") # Hello, world!
Execute the script with a console using
lily hello.lily. You should see the
message show up on your console.
It's also possible to invoke the interpreter entirely from the console:
lily -s 'print("Hello, world!")`
By default, scripts are read in code-only mode. In this mode, all input is fed
to the interpreter is read and executed. The alternative is template mode,
wherein code is between
<?lily ... ?> tags. Create another file called
template_hello.lily with the following:
<?lily ?> <html> <body> <?lily print("<p>Hello World</p>") ?> </body> </html>
Execute the script from the console using
lily -t template_hello.lily. This
time, the output will be just the html. By using the
-t switch, the executable
invokes the interpreter in template mode.
In template mode, input to the interpreter is treated as content first. Only
<?lily ... ?> tags is executed as code. Template mode files
require a tag at the very start of input. That prevents code-mode files from
being passed to template mode.
Finally, regardless of the mode that the interpreter starts in, subsequent imports always load in code-only mode. Combined with the tag restriction, it's possible to safely use code-mode libraries in template-mode modules.